China Launches Ziyuan 3, Works On New Earth-Observation Sats

BEIJING — Development of more new Chinese Earth-observation satellites is in the planning stage, national space contractor CASC says, in announcing the launch of the latest such spacecraft.

A Long March 4B rocket lofted the new satellite, Ziyuan 3, to a 500-km sun-synchronous orbit inclined at 97.5 deg. at 03:17 GMT on Jan. 9. The Xi’an launch control center reported separation of the payload and successful injection into orbit 12 min. after launch.

The 2.65-metric-ton Ziyuan 3 is China’s first civil satellite built for precision three-dimensional mapping, says CASC, whose spacecraft manufacturing subsidiary CAST built it. The satellite will provide multispectral as well as three-dimensional imaging, with a design life of five years. The launch was late; it was originally scheduled for 2011.

“Planning has begun for the development of Chinese gravity-measurement satellites, radar satellites and successors to Ziyuan 3,” CASC says, in a release that focuses purely on civil uses. It gives no more details about those planned spacecraft. The Yaogan series of remote-sensing satellites already has units with synthetic aperture radar for military use.

Use of Ziyuan 3 is officially assigned to the National Administration of Surveying, Mapping and Geoinformation, for such functions as soil monitoring and disaster mitigation. The Pentagon has said that its predecessors in the Ziyuan 1 and 2 series had potential military uses.

CASC’s full name is the China Aerospace and Technology Corp., and CAST’s is the China Academy of Space Technology. The Long March 4B is a product of another CAST unit, the Shanghai Academy of Space Flight Technology (SAST).